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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/WritingAnLLVMBackend.rst | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/docs/WritingAnLLVMBackend.rst b/docs/WritingAnLLVMBackend.rst index 35a2d164a90..429f52a3526 100644 --- a/docs/WritingAnLLVMBackend.rst +++ b/docs/WritingAnLLVMBackend.rst @@ -238,6 +238,12 @@ For some targets, you also need to support the following methods: * ``getTargetLowering()`` * ``getJITInfo()`` +Some architectures, such as GPUs, do not support jumping to an arbitrary +program location and implement branching using masked execution and loop using +special instructions around the loop body. In order to avoid CFG modifications +that introduce irreducible control flow not handled by such hardware, a target +must call `setRequiresStructuredCFG(true)` when being initialized. + In addition, the ``XXXTargetMachine`` constructor should specify a ``TargetDescription`` string that determines the data layout for the target machine, including characteristics such as pointer size, alignment, and |